1. Field of the Invention
The present invention relates to a noise insulation arrangement for reducing transmission of noise through an opening through which a transmission gear shift lever extends into a vehicle occupant compartment.
2. Description of the Prior Art
Automobiles have a transmission separated from a vehicle occupant compartment by a partition or floor panel. The transmission includes a gear shift lever assembly extending through an opening of the partition into the vehicle occupant compartment. In order to reduce noise transmission through the opening of the partition, there have been proposed various noise insulation arrangements of which two examples are described in connection with JP-B 48-30784 (U) and JP-B 5-27293 (U).
JP-B 48-30784 (U) discloses a noise insulation arrangement in which a generally conic cover is connected between a shift lever and a partition having a margin with a perimeter defining an opening through which the shift lever extends. The cover includes an inner cover portion extending from the margin toward a shift lever retainer of a transmission to fit in a peripheral notch with which the shift lever retainer is formed. The cover includes an outer conic or bellows-like cover portion extending over the inner cover. It has been also proposed to fill a chamber or space defined by the inner and outer cover portions with foamed synthetic resin. According to this known arrangement, the inner cover portion serves as a dust boot, thus unnecessiating the use of a separate dust boot.
JP-B 5-27293 (U) discloses a noise insulation arrangement that uses a single piece dust boot serving as a noise insulator. The boot includes a first boot portion connected between a shift lever ball retainer and a partition or body floor to cover an opening in which the retainer is disposed. From the shift lever ball retainer, a shift lever extends into a vehicle occupant compartment. The first boot portion is fixedly connected to the outer periphery of the shift lever ball retainer at its inner inner periphery. The first boot portion has a corrugated section and a first flat section. The first flat section lies on the corrugated section and extends beyond the outer periphery of the corrugated section to define a fixing lip placed on the partition at a margin with a perimeter defining the opening. The corrugated section extends between the perimeter defining the opening and the outer periphery of the shift lever ball retainer. At a location adjacent the periphery of shift lever ball retainer, the corrugated section is connected to a second boot portion. The second boot portion has a second flat section lying on the first flat section and a conic bellows-like section connected between the second flat section and the shift lever. The second flat section is not fixed to the first flat section but slidable to reduce resistance objectionable to smooth movement of the shift lever.
An object of the present invention is to provide a noise insulation arrangement in which such known single piece dust cover is not used.